The main problem among students is fear, when they start studying chemistry from class IX actually. Unfortunately the curriculum in all boards is designed in such a way, that the basic concepts are not clear to the students, neither do they get the joy of studying this subject. However, 95% of them take science in Classes XI and XII, but the problem remains the same! I have found in my 3 years of experience that most of the students have got a weak base in high school level. They are trying hard for the competitive exams - going to FIITJEE, AKAASH etc. But the foundation needs to be strong enough to sustain major damages and survive in LIFE !
Try to be methodical while studying Chemistry. Ist read and understand the concept of the Structure of Atom (Atomic Structure) - this is the seed of Chemistry. Then comes the Periodic Table, followed by Redox Reactions, Chemical Bonding and Acids, Bases And Salts.
These chapters are foundation for the Chemistry that we learn! If the concepts of these four chapters are clear enough and mastered by you, No one can stop you from achieving your goal !